Field of the Invention
The present invention generally relates to a control device for a hybrid vehicle equipped with an engine and an electric motor as power sources, and that is capable of selecting between an electric travel mode (EV mode) for travel executed only by the electric motor and a hybrid travel mode (HEV mode) for travel executed by the electric motor and the engine.
Background Information
For example, a hybrid vehicle such as that disclosed in Japanese Laid-Open Patent Application No. 2000-199442 is known. In this hybrid vehicle, the engine is detachably coupled to a driving wheel sequentially via a continuously variable transmission and a clutch, and an electric motor is constantly coupled to the driving wheel. The hybrid vehicle further comprises a mechanical oil pump that is driven by the engine and that supplies oil to the continuously variable transmission and the clutch.
This hybrid vehicle is capable of electric traveling (EV travel) in the EV mode by only the electric motor by stopping the engine as well as releasing the clutch described above, and is capable of hybrid traveling (HEV travel) in the HEV mode by the electric motor and the engine by starting the engine as well as engaging the clutch.
Since the engine in a stopped state and the continuously variable transmission are disconnected from the drive wheel by releasing the clutch during EV travel, the friction of the engine and the continuously variable transmission can be reduced during EV travel, and by avoiding corresponding energy loss, it is possible to increase the energy efficiency.